Photo: The original uploader was Bobak at English Wikipedia. · CC BY-SA 2.5More hazard damage per building is expected in Nantucket than in 93% of U.S. towns, mostly from hurricanes
On FEMA’s National Risk Index, Nantucket gets a D for hazard risk: higher expected damage per building than 93% of U.S. towns. Most of that expected damage is hurricanes (74%), then river and rain flooding (17%). Flood insurance has paid 472 claims here since 1978.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What stands out about Nantucket’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Nantucket faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
Hurricanes
River and rain flooding
Coastal flooding
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Nantucket’s grade
Hurricanes are 74% of the building damage FEMA expects in Nantucket, and Nantucket’s rate of hurricanes damage is in the top 3% of U.S. census tracts. Coastal flooding adds 9%, at a rate in the top 2% of U.S. census tracts.
D #282 of 283 in Massachusetts; higher expected damage per building than 93% of U.S. towns (21,298).
Nantucket’s residents live in 6 census tracts; FEMA’s figures are combined by where they live.
The typical Massachusetts town has lower expected damage than 76% of U.S. towns; within the state, Nantucket has more expected damage per building than 100% of Massachusetts towns.
In dollars, FEMA expects about $22.9M a year in losses across Nantucket: $22.3M to buildings, the rest to people and crops.
Does Nantucket flood? Yes: 472 flood claims since 1978
Every paid claim on a federal flood insurance policy in Nantucket, from FEMA’s records: 37.5 per 1,000 homes, more than 90% of the 13,809 U.S. towns with a flood insurance record.
- The “Halloween” storm138 claims · $4.9M
- The December Storm - nor’easter74 claims · $1.7M
- Hurricane Sandy11 claims · $372K
Nantucket isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Nantucket County.8 federal disasters brought FEMA money to Nantucket
Disasters that paid out in Nantucket itself (aid to households or repair grants to the Town of Nantucket), newest first, with that year’s flood claims.
- 2018Severe Winter Storm and Flooding$127K to the Town of Nantucket for repairs30 flood claims paid that year
- 2015Severe Winter Storm, Snowstorm, and Flooding$852K to the Town of Nantucket for repairs62 flood claims paid that year
- 2013Severe Winter Storm, Snowstorm, and Flooding$36K to the Town of Nantucket for repairs37 flood claims paid that year
- 2012Hurricane Sandy$31K to the Town of Nantucket for repairs11 flood claims paid for it, $372K
- 2011Hurricane Irene$7K to the Town of Nantucket for repairs
- 2010Hurricane Earl$5K to the Town of Nantucket for repairs8 flood claims paid that year
Show all 8
- 2005Record And/or Near Record Snow$119K to the Town of Nantucket for repairs1 flood claim paid that year
- 2003Snow$30K to the Town of Nantucket for repairs1 flood claim paid that year
Nantucket County has had 15 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Nantucket after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Nantucket archive →Get ready for what Nantucket faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- The season runs June through November and peaks from mid-August to mid-October.
- Bring in porch furniture and anything the wind can throw.
- Fill the gas tank and charge phones before the storm arrives.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Know your evacuation zone and the way off the coast.
- Storm surge comes fast: leave when you’re told, not when the water arrives.
- Move cars to high ground before king tides and nor’easters.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Nantucket
Is Nantucket at risk for natural disasters?
On FEMA’s National Risk Index, Nantucket has higher expected damage per building than 93% of U.S. towns: D for hazard risk. Most of the expected damage is hurricanes (74%) and river and rain flooding (17%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Nantucket flood?
Flood insurance has paid 472 claims in Nantucket since 1978, $17.7M in all, or 37.5 per 1,000 homes, more than 90% of U.S. towns with a flood insurance record. 68 properties have flooded more than once. The most claims came from The "Halloween" Storm (138).
Is Nantucket in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Nantucket County, 56% of homes in mapped flood zones carry federal flood insurance, and 7.5% of all homes do.
How much is flood insurance in Nantucket?
FEMA’s Community Rating System list shows no discount for Nantucket’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Nantucket?
By FEMA money that reached Nantucket, Severe Winter Storm, Snowstorm, and Flooding (2015): $852K to the Town of Nantucket for repairs. By flood claims, The "Halloween" Storm: 138 paid, $4.9M.
Is Nantucket at risk from hurricanes?
It is the largest share of the building damage FEMA expects here (74%), and Nantucket’s rate for it is in the top 3% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Nantucket.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Nantucket’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.